Cyanine dyestuff intermediates and process for making same



i atented June 26,1951

UNITED STATES PATENT OFFICE CYANIN E DYESTUFF INTERMEDIATES AND PROCESS FOR MAKING SAME Leo Arnold Van de Straete, Antwerp, Belgium, assignor to Gevaert Photo-Producten N. V., Mortsel-Antwerp, Belgium, a company of Belgium No Drawing. Original application June 13, 1947,

Serial No. 754,605. Divided and this application January 16, 1948, Serial No. 2,819. In the Netherlands December 12, 1940 7 Claims. 1

. The present invention relates to the manufacture of new organic compounds and particularly to the manufacture of organiccompounds suitable as intermediates for dyestuffs which may be used as sensitizers for silver halide photographic emulsions.

It is an object of my invention to provide new organic compounds.

.A further object of my invention is to provide a new process for preparing organic compounds.

. Further objects will appear from the following description.

"I have now found that suitable dyestuif intermediates of the formula wherein Y=the non-metallic atoms required for completing a fiveor six-membered heterocyclic nucleus occasionally having a benzene or naphthalene nucleus fused on,

R and R1=alky1 or substituted alkyl,

X=an acid residue e. g. Cl, Br, I, CH3SO4 and 0104, may be manufactured from Z-methylcyclammcnium salts.

From these Z-methyl-cyclammonium salts, Z-methylene bases are produced (A). The 2- methylene bases are caused to react with carbon sulphide (B) and the additive compounds are converted into esters by means of alkylating agents (C). The three steps A, B and C, are illustrated by the following examples: Herein the temperatures are stated in centigrade.

A. THE PREPARATION OF THE Z-METHYLENE BASES Cyclammonium salts with a reactive methyl group in alpha position to the N-atom are treated by strong bases as for instance NaOH.

Example 1.--2-methylene-3-methyZ-betanapthothiazoline 16 g. of 2-methyl-beta-naphthothiazole dimethyl sulphate are dissolved in 200 cm. of ethyl alcohol. Next 8 g. of sodium hydroxide and 10 c. c. of water are added. After vigorously shaking until dissolution of the sodium hydroxide, about 7.6 g. of 2- methylene base are precipitated. Melting point is 147 C. (after thoroughly washing with water, alcohol and ether).

Reaction-scheme zothiazoline 12 g. of 2-6-dimethyl benzothiazole dimethyl sulphate are dissolved in 150 c. c. of acetone. The solution is treated with 6 g. of sodium hydroxide and 7 cm. of water. After separating and adding water to the acetone layer, 7 g. of methylene base are precipitated. Melting point is 168.

om- 6 7 s 5 3 2C I=CHz Example 3.1-ethg1l-2-methyZene-6- methoxyquinoline 10 g. of G-methoxy quinaldine ethyl bromide are dissolved in 10 c. c. of water. Next c. c. of sodium hydroxide solution 2 N are introduced.

40 The methylene base crystallizes out as brown powder. Melting point is 105. Yield 4.3 g.

(BzHg Example 4.--2-methyZene-3-ethyl benzothiazoline 16 g. of 2-methyl benzothiazole di-ethyl sulphate are dissolved in 200 cm. of acetone. Next 8 g. of sodium hydroxide and 10 c. c. of water are added. Further treatment as for the 3-6-dimethyl base. Melting point is 136. Yield 6 g.

In the same way are obtained 2-methylene-3-benzyl benzothiazoline. (melting point at 143) 2-methylene-3-methy1-alpha naphthothiazoline (melting point at 180) 2-methylene-3-methyl-6-chloro benzothiazoline (melting point at 155) 2 methylene-S-methyl 6 methoxybenzothiazoline (melting point at 136) 2 methylene 3 6 dimethylbenzoselenazoline (melting point at 167) 2-methylene-3-methyl 6 acetylaminobenzothiazoline (melting point at 105) 2.-.methylene-.3 ethylbenzoselenazoline (melting point at 138).

B. ADDITION OF CARBON SULPHIDE TO THE METHYLENE BASES These Z-methylene bases form with carbon sulphide very characteristic additive compounds of the following probable formula:

As examples of these additive compounds as well as of the process for their preparation may be cited:

Ezvample 5.,2;methylidene dithiocarboxylic acid of N-methyl beta-naphthoth azol 12 g. of 2-methylene 3emethyl-beta-naphthothiazoline are dissolved in 8 litres of anhydrous alcohol. Next 135 c. c. of carbon sulphide are added. After-keeping-B days at ordinary temperature a yellow-powder is separated. Melting point 264 (after washing with boiling alcohol). The product is insoluble in the usual solvents. Yield 6.4 g.

Example 6.- 2-methy lidene dithiocarboxylic dcz'd of; 3-6- dimethyl benzothiazol .47, g., of 2-methylene-3-6-dimethylbenzothiazqlineare. dissolved in 750 cm. of benzene. Next 21 c.,c. of carbon sulphide areintroduced. After two days a yellow deposit is obtained. Melting point 231 (after crystallisation from pyridine). Yield 11.5 s.

CH3" S Example- 7.-.2,-methylidene dithiocarboxylic acid I of -3 -methylbenzo selenazol 6 g; of 2-methylene-N-methylbenzoselenazoline are dissolved in c. c. of ethyl alcohol and 25 c. c. of carbon sulphide are added. After two days 1.5 g. of additive compound is obtained. Melting point 237.

By proceeding in the same way are also obtained:

Z-methylidene dithiocarboxylic acid of 3-benzylbenzothiazol (melting point 235) 2-methylidene dithiocarboxylic acid of 3-methylalpha-naphthothiazol (melting point 275) 2-methylidene dithiocarboxylic acid of 3-methyl- 6-chloro-benzothiazol (melting point 288) Z-methylidene dithiocarboxylic acid of 3-ethyl- 6 dimethylaminobenzothiazol (melting point 225) 2-methylidene dithiocarboxylic acid of 3em ethyl- 6-dimethylaminobenzothiazol (melting point 240) Z-methylidene dithiocarboxylic acid of 3-ethyl- C. PREPARATION OF THE ESTERS From the additive compounds. may finally be obtained, by addition of an .alkyl ester or substituted alkyl ester, as for instance dimethyl sulphate, thedesired intermediate substances of the following probableformula:

Other examples :01 such esters are: diethyl sul phate, ethyl-ester ofpara-toluene sulphonicacid, methyl ester of para-toluene sulphonic acid, benzyl ester of para-toluene sulphonic acid.

The reaction isfurther illustrated by the following examples:

Example 8 2.4 g. of N-methyl-2-methy1idene-benzothiaz olinedithiocarboxylic acid are heated with 3.8

. solidifies.

is Obtained. Melting point 165.

g; of dimethyl sulphate at 125-130 during two hours. By cooling, the liquid reaction mixture On crystallizing from methyl alcohol, in which the non-alkylated acid is insoluble, an intermediate substance corresponding to the following formula 0 S son.

J:-oH=t:-soH,

CHQSOI precipitates. Melting point 230. Determination of S; 33.57%. Calculated amount 33.70%.

Example 9 2.9 g. of N-methyl-Z-methylidene benzoselenazoline dithiocarboxylic acid are heated with 3.8 g. of dimethyl sulphate at 125 during two hours. After cooling, the mass, which has again solidified, is recrystallized from methyl alcohol and an intermediate substance of the probable formula.

59 SCH; -CH=(JSCH; on, 'CH$S0t is obtained. Melting point 228.

Example 10 10 g. of N-methyl-2-methylidene benzoselenazoline-dithiocarboxylic acid are heated with c. c. of diethyl sulphate on a glycerol bath at 125 for three hours. washed with ether and dissolved in 125 c. c. of

methyl alcohol. After filtration, 75 c. c. of a 20% potassium bromide solution are added. Freed by filtration from insoluble secondary products, the solution is treated with 200 cm. ether and cooled to 0. An intermediate substance of the probable formula Yield 6.5 g.

Example 11 I 10 g. of N-methyLZ-methylidene berizothiazoline dithiocarboxylic acid are heated with 20 c. c.- of diethyl sulphate on a glycerol. bath at 125-130 for two hours. After cooling, the mixture is dissolved in methyl alcohol and on addition of a solution of potassium iodide 10%, an intermediate substance of the probable formula.

scar.

is obtained. The product is recrystallized from methyl alcohol. Melting point 178.

Example 12 10 g. of N-methyl-2-methylidene-beta-naphthothiazoline dithiocarboxylic. acid are heated After cooling, the mixture is with 30 c. c. of diethyl sulphate at 125 C. during five hours. 'After cooling, the solidified reaction mixture is dissolved in c. c. of ethyl alcohol and precipitated with a solution of potassium bromide 10%. After twenty-four hours a dark colored half-solid deposit is formed. This is dissolved in alcohol, and other is added to the cooled solution. Melting point 177. The product corresponds probably with the formula:

Example 13 20 g. of 3-6-dimethyl-2methylidene benzothiazole dithiocarboxylic acid are heated with 40 c. c. of diethyl sulphate at 125 during two hours. After cooling, the mixture is washed with ether and dissolved in alcohol. This solution is treated with potassium iodide. After several hours, the deposit obtained is treated with alcohol and so freed from insoluble secondary products. The solution is treated with ether and an intermediate substance of the probable formula solHi -CH=$SCIH5 C \I precpitates. The solution is crystallized from methyl alcohol. Melting point 197. Yield 8 g.

Example 14 7 g. of Z-ethylidene 3 methylbenzothiazole dithiocarboxylic acid and 14 c. c. of diethyl sulphate are heated at 125 C. during minutes. The product so obtained is washed with ether and dissolved in 50 cm? of methyl alcohol. A solution of potassium iodide 10% is added. After several hours, an intermediate substance of the probable formula 5 on. scar. t-o -so.n.

wherein Y represents the non-metallic atoms necessary for completing a member selected from the group consisting of 5- and S-membered heterocyclic rings and 5- and G-membered hetero cyclic rings bearing a fused-on arylene group, R and R1 both represent an alkyl group, and X represents an acid residue, which comprises effecting a condensation of a nitrogen-containing methylene base of the formula wherein Y' and R have the same significance as above, with carbon sulphide, and converting such condensation product into an ester by treating same with an alkylati'ng agent.

2. A process of makinga dyestuff intermediate having the formula the group consisting of H and alkyl, X is an acidresidue, which comprises condensing with carbon disulphide, in the presence of an alkali metal hydroxide, a compound of the formula X C-CH:

wherein R, X and Y have the same significance as. above, and forming an ester by treating with analkylating agent.

3. A' process'of producing a derivative of a cyclammonium salt having the formula in which Y represents the non-metallic atoms necessary for completing a member selected from the group consisting of and fi-membered hetero'cyclic rings and 5- and G-membered heterocyclic rings bearing a fused-on arylene nucleus and R, R and R are alkyl and X is an acid residue, which comprises transforming the addition product of a cyclic nitrogen-containing alkylene base of the formula wherein X and B have the significance as given hereinabove, with carbon disulphide, into an ester 8 by treating such addition product into an ester by treating same with an alkylating agent.

4. A dyestuff intermediate of the general formula':

wherein Y=the non-metallic atoms required for completing a member selected from the group consisting of 5- and G-membered heterocyclic rings and 5- and G-membered heterocyclic ring systems having a fused-on arylene group, R, R and R =alkyl and X=an acid residue.

5. 2-(beta-dimethyl mercapto vinyl) -benz0- seleneazole dimethyl sulphate of the formula:

Se s CH:

6. 2(beta-diethyl mercapto vinyl) -beta-naphthothiazole methyl halide of the formula:

CH3 X wherein X=a member selected from the group consisting of Br and I.

'7. Z-(beta-dimethyl mercapto vinyl)-benzothiazole dimethyl sulphate of the formula:

LEO ARNOLD VAN DE STRAETE.

REFERENCES CITED The following references are of record in the file ofthispatenti.

UNITED STATES PATENTS Number Name Date 2,332,517 Kendall et a1 Oct. 26,- 1943 2,334,711 Kendall et a1 -Nov. 23, 1943 

1. A PROCESS OF MAKING A DERIVATIVE OF A CYCLAMMONIUM SALT OF THE FORMULA 